In the Supreme Court, there are 9 judges. It is customary for all judges to shake each other's hands when they enter a room together. How many handshakes occur in the room with 9 people? Show multiple representations to provide evidence of your answer. Include a table, diagrams for different amounts of people, starting with 2 (since 1 person can't shake his own hand), and even coming up with an expression or equation to get the answer.

Please help me. It’ll be super helpful if you could do it on a paper and take a pic for me I’ll give you a brainliest + 20 points